Wireless communication systems of various kinds are known in the art. Some of these systems make use of statically or dynamically arranged transmitter-receiver configurations. The Universal Mobile Telecommunications System (UMTS) comprises an illustrative example in this regard. In such a system a given transmitter-receiver configuration can be represented as a corresponding precoding matrix indicator or index (often denoted by its acronym, PMI) which serves, for example, to indicate at least one of a transmission rank and/or a valid codebook entry.
In many cases, such a system will accommodate use of any of a variety of transmitter-receiver configurations. This capability, in turn, can be leveraged to facilitate effective management of the communications resources as comprise such a system. For example, by one approach, a given mobile station can propose a given PMI to be used in conjunction with subsequent communications such as a subsequent downlink communication to the mobile station. A receiving base station (such as a so-called Node B in a UMTS environment or an evolved Node B or ‘eNode B’ or ‘eNB’ in an Evolved UMTS environment) can indicate its reception and acknowledgement of such a request by echoing that same PMI back to the mobile station.
Though such an approach tends to provide an effective validation mechanism, this benefit comes at a price. For example, echoing the PMI back to the mobile station can result in a considerable amount of layer 1 and layer 2 (L1/L2) control channel overhead especially for larger code-book sizes and if frequency selective precoding is used requiring a separate PMI for each group of channel resources reported on. Given a single L1/L2 downlink control channel embodiment, the resulting fixed PMI overhead can be inefficient for base station and mobile station wireless communications that do not use precoding. Avoiding this inefficiency can also necessitate a relatively complicated L1/L2 control channel design to accommodate such PMI information (since, for example, the number of required bits can vary given frequency selective precoding feedback).
While precoding activities comprise an important and desired behavior, such precoding can lead to undesirable results without a corresponding verification mechanism. As noted above, however, verification carries its own undesirable costs with respect to design and operational requirements.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.